From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 000F2C433E0 for ; Thu, 4 Feb 2021 13:51:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5CFC64F45 for ; Thu, 4 Feb 2021 13:51:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236323AbhBDNvM (ORCPT ); Thu, 4 Feb 2021 08:51:12 -0500 Received: from mx2.suse.de ([195.135.220.15]:32952 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236393AbhBDNuc (ORCPT ); Thu, 4 Feb 2021 08:50:32 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 65AF5AC97; Thu, 4 Feb 2021 13:49:49 +0000 (UTC) Message-ID: <1612446586.7566.20.camel@suse.cz> Subject: Re: [PATCH v3 1/1] x86,sched: On AMD EPYC set freq_max = max_boost in schedutil invariant formula From: Giovanni Gherdovich To: "Rafael J. Wysocki" Cc: "Rafael J. Wysocki" , Borislav Petkov , Ingo Molnar , Peter Zijlstra , Viresh Kumar , Jon Grimm , Nathan Fontenot , Yazen Ghannam , Thomas Lendacky , Suthikulpanit Suravee , Mel Gorman , Pu Wen , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Michael Larabel , the arch/x86 maintainers , Linux PM , Linux Kernel Mailing List , ACPI Devel Maling List Date: Thu, 04 Feb 2021 14:49:46 +0100 In-Reply-To: <5470319.60Xv9dOaFs@kreacher> References: <20210203135321.12253-1-ggherdovich@suse.cz> <20210203135321.12253-2-ggherdovich@suse.cz> <5470319.60Xv9dOaFs@kreacher> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Wed, 2021-02-03 at 19:25 +0100, Rafael J. Wysocki wrote: > [cut] > > So below is a prototype of an alternative fix for the issue at hand. > > I can't really test it here, because there's no _CPC in the ACPI tables of my > test machines, so testing it would be appreciated. However, AFAICS these > machines are affected by the performance issue related to the scale-invariance > when they are running acpi-cpufreq, so what we are doing here is not entirely > sufficient. > > It looks like the scale-invariance code should ask the cpufreq driver about > the maximum frequency and note that cpufreq drivers may be changed on the > fly. > > What the patch below does is to add an extra entry to the frequency table for > each CPU to represent the maximum "boost" frequency, so as to cause that > frequency to be used as cpuinfo.max_freq. > > The reason why I think it is better to extend the frequency tables instead > of simply increasing the frequency for the "P0" entry is because the latter > may cause "turbo" frequency to be asked for less often. > > --- > drivers/cpufreq/acpi-cpufreq.c | 107 ++++++++++++++++++++++++++++++++++++----- > 1 file changed, 95 insertions(+), 12 deletions(-) Hello Rafael, thanks for looking at this. Your patch is indeed cleaner than the one I proposed. Preliminary testing is favorable; more tests are running. Results from your patch are in the fourth column below; the performance from v5.10 looks restored. I'll follow up once the tests I queued are completed. Giovanni TEST : Intel Open Image Denoise, www.openimagedenoise.org INVOCATION : ./denoise -hdr memorial.pfm -out out.pfm -bench 200 -threads $NTHREADS CPU : MODEL : 2x AMD EPYC 7742 FREQUENCY TABLE : P2: 1.50 GHz P1: 2.00 GHz P0: 2.25 GHz MAX BOOST : 3.40 GHz Results: threads, msecs (ratio). Lower is better. v5.10 v5.11-rc4 v5.11-rc4-ggherdov v5.11-rc6-rafael ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1 1069.85 (1.00) 1071.84 (1.00) 1070.42 (1.00) 1069.12 (1.00) 2 542.24 (1.00) 544.40 (1.00) 544.48 (1.00) 540.81 (1.00) 4 278.00 (1.00) 278.44 (1.00) 277.72 (1.00) 277.79 (1.00) 8 149.81 (1.00) 149.61 (1.00) 149.87 (1.00) 149.51 (1.00) 16 79.01 (1.00) 79.31 (1.00) 78.94 (1.00) 79.02 (1.00) 24 58.01 (1.00) 58.51 (1.01) 58.15 (1.00) 57.84 (1.00) 32 46.58 (1.00) 48.30 (1.04) 46.66 (1.00) 46.70 (1.00) 48 37.29 (1.00) 51.29 (1.38) 37.27 (1.00) 38.10 (1.02) 64 34.01 (1.00) 49.59 (1.46) 33.71 (0.99) 34.51 (1.01) 80 31.09 (1.00) 44.27 (1.42) 31.33 (1.01) 31.11 (1.00) 96 28.56 (1.00) 40.82 (1.43) 28.47 (1.00) 28.65 (1.00) 112 28.09 (1.00) 40.06 (1.43) 28.63 (1.02) 28.38 (1.01) 120 28.73 (1.00) 39.78 (1.38) 28.14 (0.98) 28.16 (0.98) 128 28.93 (1.00) 39.60 (1.37) 29.38 (1.02) 28.55 (0.99)